From: Wolfgang Bangerth Date: Mon, 15 May 2023 20:57:48 +0000 (-0600) Subject: Update output of step-77. X-Git-Tag: v9.5.0-rc1~226^2 X-Git-Url: https://gitweb.dealii.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=45eeb0629dea7827a47e0018f24b1538eb74b113;p=dealii.git Update output of step-77. --- diff --git a/examples/step-77/doc/results.dox b/examples/step-77/doc/results.dox index 5762f68af1..5db6f9e1d8 100644 --- a/examples/step-77/doc/results.dox +++ b/examples/step-77/doc/results.dox @@ -5,132 +5,95 @@ When running the program, you get output that looks like this: Mesh refinement step 0 Target_tolerance: 0.001 - Computing residual vector... norm=0.231202 + Computing residual vector... norm=0.867975 Computing Jacobian matrix Factorizing Jacobian matrix Solving linear system - Computing residual vector... norm=0.231202 - Computing residual vector... norm=0.171585 + Computing residual vector... norm=0.867975 + Computing residual vector... norm=0.212073 Solving linear system - Computing residual vector... norm=0.171585 - Computing residual vector... norm=0.127245 - Computing residual vector... norm=0.0796471 + Computing residual vector... norm=0.212073 + Computing residual vector... norm=0.202631 Solving linear system - Computing residual vector... norm=0.0796471 - Computing residual vector... norm=0.0625301 + Computing residual vector... norm=0.202631 + Computing residual vector... norm=0.165773 Solving linear system - Computing residual vector... norm=0.0625301 - Computing residual vector... norm=0.0498864 + Computing residual vector... norm=0.165774 + Computing residual vector... norm=0.162594 Solving linear system - Computing residual vector... norm=0.0498864 - Computing residual vector... norm=0.0407765 + Computing residual vector... norm=0.162594 + Computing residual vector... norm=0.148175 Solving linear system - Computing residual vector... norm=0.0407765 - Computing residual vector... norm=0.0341589 + Computing residual vector... norm=0.148175 + Computing residual vector... norm=0.145391 Solving linear system - Computing residual vector... norm=0.0341589 - Computing residual vector... norm=0.0292867 + Computing residual vector... norm=0.145391 + Computing residual vector... norm=0.137551 Solving linear system - Computing residual vector... norm=0.0292867 - Computing residual vector... norm=0.0256309 - Computing residual vector... norm=0.0223448 + Computing residual vector... norm=0.137551 + Computing residual vector... norm=0.135366 Solving linear system - Computing residual vector... norm=0.0223448 - Computing residual vector... norm=0.0202797 - Computing residual vector... norm=0.0183817 + Computing residual vector... norm=0.135365 + Computing residual vector... norm=0.130367 Solving linear system - Computing residual vector... norm=0.0183817 - Computing residual vector... norm=0.0170464 - Computing residual vector... norm=0.0157967 + Computing residual vector... norm=0.130367 + Computing residual vector... norm=0.128704 Computing Jacobian matrix Factorizing Jacobian matrix Solving linear system - Computing residual vector... norm=0.0157967 - Computing residual vector... norm=0.0141572 - Computing residual vector... norm=0.012657 + Computing residual vector... norm=0.128704 + Computing residual vector... norm=0.0302623 Solving linear system - Computing residual vector... norm=0.012657 - Computing residual vector... norm=0.0116863 - Computing residual vector... norm=0.0107696 + Computing residual vector... norm=0.0302624 + Computing residual vector... norm=0.0126764 Solving linear system - Computing residual vector... norm=0.0107696 - Computing residual vector... norm=0.0100986 - Computing residual vector... norm=0.00944829 - Computing residual vector... norm=0.00822576 + Computing residual vector... norm=0.0126763 + Computing residual vector... norm=0.00488315 Solving linear system - Computing residual vector... norm=0.00822576 - Computing residual vector... norm=0.00781983 - Computing residual vector... norm=0.00741619 - Computing residual vector... norm=0.00661792 + Computing residual vector... norm=0.00488322 + Computing residual vector... norm=0.00195788 Solving linear system - Computing residual vector... norm=0.00661792 - Computing residual vector... norm=0.00630571 - Computing residual vector... norm=0.00599457 - Computing residual vector... norm=0.00537663 - Solving linear system - Computing residual vector... norm=0.00537663 - Computing residual vector... norm=0.00512813 - Computing residual vector... norm=0.00488033 - Computing residual vector... norm=0.00438751 - Computing residual vector... norm=0.00342052 - Solving linear system - Computing residual vector... norm=0.00342052 - Computing residual vector... norm=0.00326581 - Computing residual vector... norm=0.00311176 - Computing residual vector... norm=0.00280617 - Computing residual vector... norm=0.00220992 - Solving linear system - Computing residual vector... norm=0.00220992 - Computing residual vector... norm=0.00209976 - Computing residual vector... norm=0.00199943 - Solving linear system - Computing residual vector... norm=0.00199942 - Computing residual vector... norm=0.00190953 - Computing residual vector... norm=0.00182005 - Computing residual vector... norm=0.00164259 - Computing residual vector... norm=0.00129652 + Computing residual vector... norm=0.00195781 + Computing residual vector... norm=0.000773169 +---------------------------------------------+------------+------------+ -| Total wallclock time elapsed since start | 0.192s | | +| Total wallclock time elapsed since start | 0.121s | | | | | | | Section | no. calls | wall time | % of total | +---------------------------------+-----------+------------+------------+ -| assembling the Jacobian | 2 | 0.0141s | 7.4% | -| assembling the residual | 61 | 0.168s | 88% | -| factorizing the Jacobian | 2 | 0.0016s | 0.83% | -| graphical output | 1 | 0.00385s | 2% | -| linear system solve | 19 | 0.0013s | 0.68% | +| assembling the Jacobian | 2 | 0.0151s | 12% | +| assembling the residual | 31 | 0.0945s | 78% | +| factorizing the Jacobian | 2 | 0.00176s | 1.5% | +| graphical output | 1 | 0.00504s | 4.2% | +| linear system solve | 15 | 0.000893s | 0.74% | +---------------------------------+-----------+------------+------------+ Mesh refinement step 1 Target_tolerance: 0.0001 - Computing residual vector... norm=0.0883422 + Computing residual vector... norm=0.2467 Computing Jacobian matrix Factorizing Jacobian matrix Solving linear system - Computing residual vector... norm=0.0883422 - Computing residual vector... norm=0.0607066 - Solving linear system - Computing residual vector... norm=0.0607066 - Computing residual vector... norm=0.0437266 + Computing residual vector... norm=0.246699 + Computing residual vector... norm=0.0357783 Solving linear system - Computing residual vector... norm=0.0437266 - Computing residual vector... norm=0.0327999 + Computing residual vector... norm=0.0357784 + Computing residual vector... norm=0.0222161 Solving linear system - Computing residual vector... norm=0.0327999 - Computing residual vector... norm=0.0255418 + Computing residual vector... norm=0.022216 + Computing residual vector... norm=0.0122148 Solving linear system - Computing residual vector... norm=0.0255417 - Computing residual vector... norm=0.0206042 + Computing residual vector... norm=0.0122149 + Computing residual vector... norm=0.00750795 Solving linear system - Computing residual vector... norm=0.0206042 - Computing residual vector... norm=0.0171602 + Computing residual vector... norm=0.00750787 + Computing residual vector... norm=0.00439629 Solving linear system - Computing residual vector... norm=0.0171602 - Computing residual vector... norm=0.014689 + Computing residual vector... norm=0.00439638 + Computing residual vector... norm=0.00265093 Solving linear system [...] @@ -143,18 +106,25 @@ Mesh refinement step 0 Mesh refinement step 0 Target_tolerance: 0.001 - Computing residual vector... norm=0.231202 + Computing residual vector... norm=0.867975 Computing Jacobian matrix Factorizing Jacobian matrix Solving linear system - Computing residual vector... norm=0.231202 - Computing residual vector... norm=0.171585 + Computing residual vector... norm=0.867975 + Computing residual vector... norm=0.212073 Solving linear system - Computing residual vector... norm=0.171585 - Computing residual vector... norm=0.127245 - Computing residual vector... norm=0.0796471 + Computing residual vector... norm=0.212073 + Computing residual vector... norm=0.202631 + Solving linear system + Computing residual vector... norm=0.202631 + Computing residual vector... norm=0.165773 + Solving linear system + Computing residual vector... norm=0.165774 + Computing residual vector... norm=0.162594 + Solving linear system + Computing residual vector... norm=0.162594 + Computing residual vector... norm=0.148175 Solving linear system - Computing residual vector... norm=0.0796471 ... @endcode What is happening is this: @@ -169,11 +139,15 @@ What is happening is this: i.e., do line search. To this end, KINSOL requires us to compute the residual vector $F(U_k + \alpha_k \delta U_k)$ for different step lengths $\alpha_k$. For the first step above, it finds an acceptable $\alpha_k$ - after two tries, the second time around it takes three tries. + after two tries, and that's generally what will happen in later line + searches as well. - Having found a suitable updated solution $U_{k+1}$, the process is repeated except now KINSOL is happy with the current Jacobian matrix and does not instruct us to re-build the matrix and its factorization, - and instead asks us to solve a linear system with that same matrix. + instead asking us to solve a linear system with that same matrix. That + will happen several times over, and only after ten solves with the same + matrix are we instructed to build a matrix again, using what is by then an + already substantially improved solution as linearization point. The program also writes the solution to a VTU file at the end of each mesh refinement cycle, and it looks as follows: @@ -202,6 +176,7 @@ The key takeaway messages of this program are the following: times, without us having to implement the intricacies of algorithms that determine when we need to rebuild this information. +

Possibilities for extensions